This invention is concerned with a flame-retardant molded component. The invention is particularly applicable to monofilaments for formation into braided sleeves used to protect electrical wires or pipes.
It is well-known to form molded components from polymers such as nylon 6. For example, braided sleeves used for protecting wires or pipe from abrasion damage, for example, in an engine compartment of a vehicle, are often formed from monofilaments of nylon 6. The monofilaments have a diameter of about 0.25 mm to about 3.25 mm.
It is also well-known to provide polyamides, e.g., nylon 6 or nylon 66, or other polymers with flame-retardancy properties by filling them with flame-retardant materials. Typical applications include molded containers for electrical equipment and coatings for electrical wires. Melamine cyanurate is a known flame-retardant filler for use in polyamides for such applications. In the event of fire, the melamine cyanurate decomposes giving off flame-retardant gases. However, as the proportion of melamine cyanurate increases, the flexibility and surface quality of the material decreases making the material prone to cracking. For this reason, providing sufficient melamine cyanurate for the required flame-retardancy renders the material unsuitable for many uses, for example, for forming into the above-mentioned monofilaments. For this reason, the protective sleeves referred to above are not formed from flame-retardant monofilaments despite the obvious fire risks present in engine compartments.
Polyphosphonates are known as flame-retardant fillers in some polymeric matrices. However, they are not effective enough when used alone to enable a molded component to pass flame-retardancy tests.
It is an object of the present invention to provide a flame-retardant molded component which combines good flame-retardancy properties with good flexibility and good surface quality.